Senior Security Engineer

Nansen surfaces the signal and creates winners in the future of finance. We're building a new way to trade: agentic, onchain, and fully integrated. From analytics to execution, we're the platform where investors find alpha and act on it. The Opportunity As we scale our product, staking operations, and AI-powered capabilities, security matters more than ever. We're hiring a Senior Security Engineer to strengthen our security posture across the entire engineering organisation. You'll work closely with the Head of Security and collaborate hands-on with engineering teams across the company to ensure that the systems we build are secure by design. This is a generalist security role. You'll operate across application security, cloud infrastructure security, and organizational security practices. It's ideal for someone who thrives in a high-autonomy environment, is comfortable spanning multiple security domains, and wants to have outsized impact at a growing company. What You'll Do • Conduct security reviews of systems, architectures, and code — proactively identifying and addressing vulnerabilities. • Serve as a go-to security advisor for engineering teams, helping them make secure design decisions. • Define and implement security standards across cloud infrastructure, applications, and blockchain systems. • Implement and maintain security tooling: vulnerability scanning, endpoint protection, SIEM, logging and monitoring. • Secure CI/CD pipelines and deployment workflows from a security perspective. • Secure internal AI tools and LLM integrations — from API key management and prompt injection prevention to evaluating the security implications of AI adoption across the organization. • Manage and improve secrets management, key management, and access control practices across the organization. • Define and maintain secure coding guidelines and security review processes for engineering teams. • Collaborate with external providers on penetration tests and security audits, ensuring findings are prioritized and remediated. • Participate in incident response: investigation, containment, root cause analysis, and post-incident improvements. • Support compliance and audit readiness by implementing required security controls and maintaining documentation. What We're Looking For • Strong understanding of cloud security (AWS, GCP, or similar), container security, and network security fundamentals. • Hands-on experience implementing and operating security tools (SIEM, vulnerability scanners, endpoint protection, cloud security tooling). • Experience with secrets management, key management, and encryption best practices. • Experience securing AI/LLM tooling, agent-based systems, and modern developer platforms. • Familiarity with securing CI/CD pipelines and developer tooling. • Solid understanding of compliance framew